I was wondering how people are able to create a screw post in their case for holding bread board or something like that? Do u just take one from somehwere else and glue it to the case?

That's silly. Why spend money?

Just rip them out of whatever you just took apart. N64's have like 12 screwposts in them.

You can also stack pieces of plastic, glue them, and drill a hole down the middle.